ADM1070

a FEATURES Allows Safe Board Insertion and Removal from a Live –48 V Backplane Typically Operates from –36 V to –80 V Tolerates Transients up to –200 V (Limited by External Components) Accurate Programmable Linear Current Limit for In-Rush Control and Short Circuit Protection Programmable Timeout in Current Limit Limited Consecutive Retry: Auto-Restart after Current Limit Timeout Shutdown after Seven Consecutive Auto Restarts Provides Immunity from Step Induced Current Spikes Default Timing Provided with no TIMER Capacitor Single Pin Undervoltage/Overvoltage Detection Programmable Operating Voltage Window Programmable Undervoltage/Overvoltage Time Filter Small 6-Lead SOT-23 Package APPLICATIONS Central Office Switching –48 V Distributed Power Systems Negative Power Supply Control Hot Board Insertion Electronic Circuit Breaker High Availability Servers Programmable Current Limiting Circuit –48 V Power Supply Modules –48 V Hot Swap Controller ADM1070 FUNCTIONAL BLOCK DIAGRAM 0V VDD RDROP 16k⍀ VIN CLOAD VOUT R1 VCC AND VCC REFERENCE 12V GENERATOR VREF UV/OV R2 TIMER ( )* –48V VEE OVER-UNDER VOLTAGE DETECTION CIRCUIT 100mV EN VIN 45␮A FAULT TIMER AND CONTROL Q1 GATE OSCILLATOR ADM1070 SENSE RSENSE VEE *OPTIONAL TIMER CAPACITOR GENERAL DESCRIPTION The ADM1070 is a negative voltage hot swap controller that allows a board to be safely inserted and removed from a live –48 V backplane. The part achieves this by providing robust current limiting, protection again...